With sales of existing homes in Canada rising in October to the highest level since January, the Canadian Real Estate Association boosted its forecast for resale activity for 2011.

The industry group released data on October sales activity as well as a revised forecast for the year on Tuesday. [np-related]

National sales of existing homes increased 1.2% from the previous month, building on a gain of 2.5% in September. Price gains however cooled to 5.5%, the smallest gains since January.

A total of 397,561 resale units have traded hands so far this year, CREA said, up 1.8% from levels in the first 10 months of 2010.

Here’s what you need to know about the booming Canadian housing market:

Ontario leads the way

Third-quarter sales activity in the province was stronger than forecast, while the rest of the country came in broadly in line with expectations, the CREA said.

It was the strength of activity in Ontario that prompted the CREA to boost its annual forecast for 2011 to 1.4%, up from 0.9%.

The industry group now predicts national sales of 453,300 for the year, compared with 446,915 in 2010.

198,000 of 2011’s residential sales are expected to come from Ontario, with Quebec and British Columbia expected to have sales of 77,000 and 76,600, respectively.

Home prices are still up but showing signs of cooling down

CREA kept its national average home price forecast for the year little changed at $362,700. That’s an annual increase of 7.0% compared with $339,049 in 2010.

Prices are expected to remain flat next year, with the CREA forecasting $362,700 again for 2012.

The industry group pointed to moderating prices in Vancouver in the third quarter compared with the first half of the year, with sales of multi-million dollar properties in that city returning to “more normal levels.”

CREA said the national average price in October rose 5.5% from a year earlier to just under $362,899, the smallest increase since January.

The balance of supply and demand is tight but the market remains on solid footing

October’s monthly rise in sales resulted in a slightly tighter balance of supply and demand, but the national housing market remains “firmly rooted in balanced territory,” the CREA said.

The national sales-to-new listings ratio, a measure of market balance, stood at 53.4% in October, up from 52.8% in September.

Low interest rates continue to bolster the market

CREA also revised its forecast for 2012 upward slightly, predicting a smaller easing than previously expected of 0.5% to 451,200 units.

The uptick is largely due to expectations that Canada’s interest rates will stay low until well into 2012, CREA said.

But domestic and global economic headwinds could put pressure on the sector